In order to test whether gene-engineered endothelial cells would adhere and thrive and express a recombinant marker when introduced into a segment of arterial graft, it is necessary to provide a mock circulatory system or surgically implant the graft into a living host animal. The present work provides a system whereby tissue culture fluid is presented to the graft segment containing the altered cells at pulse pressures and flow values mimicking host values that would be encountered by a graft implanted in a living animal. The mock circulation is designed to maintain a biochemical milieu consistent with optimal tissue growth and survival while challenging the adhesive and secretory activity through the mechanical forces tending to dislodge the grafted cells. Having confirmed that the general procedure establishes functional endothelium on the grafts the problem now is to try the methods on various graft materials and expose them to relatively comparable hydrodynamic conditions and quantify the effectiveness of the cells to express their genetically modified functions.